Swivel chair or like article of furniture



July 28, 1964 B. s. SILVER 3,142,471

SWIVEL CHAIR OR LIKE ARTICLE OF FURNITURE Filed Sept. 21. 1961 2 Sheets-Sheet 1 INVENTOR Bmre/m F1134 new ATTORNEY July 28, 1964 B. s. SILVER 3,142,471

SWIVEL CHAIR 0R LIKE ARTICLE OF FURNITURE Filed Sept. 21, 1961 2 Shets-Sheet 2 INVENT R 350779407157 41 50 ATTORNEY United States Patent 3,142,471 SWIVEL CHAIR OR LIKE ARTICLE OF FURNITURE Bertram S. Silver, 150 Central Park S., New York, NY. Filed Sept. 21 1961, Ser. No. 139,705

2 Claims. (Cl. 248417) The present invention relates generally to an improved article of furniture, and it relates particularly to an improved swivel chair.

The use of swivel chairs under varying conditions affords a number of advantages over the conventional fixed position chair. Principal among these is that it permits the free variation in the orientation of the occupant. However, free rotatability of the seat of the conventional swivel chair creates certain drawbacks and a chair so equipped lacks many of the advantages of the fixed position seat type of chair. Thus, the stability of a fixed seat which is often highly desirable is absent in the swivel chairs heretofore available which otherwise leave much to be desired.

It is, therefore, a principal object of the present invention to provide an improved article of furniture of the swivel chair type.

Another object of the present invention is to provide an improved chair possessing the advantages of a swivel chair type as well as those of the conventional fixed position chair type, while lacking their drawbacks.

Still another object of the present invention is to provide an improved chair of the above nature characterized by its simplicity, ruggedness, ease of operation, and low cost.

The above and other objects of the present invention will become apparent from a reading of the following description, taken in conjunction with the accompanying drawings, wherein FIGURE 1 is a front perspective view of a swivel chair embodying the present invention;

FIGURE 2 is an exploded fragmentary perspective view of the improved swivel and support mechanism;

FIGURE 3 is a bottom plan view of the seat, a swivel structure illustrated in a normal or stable position;

FIGURE 4 is a view similar to FIGURE 3, the seat being illustrated in an unstable or stressed position removed from its normal equilibrium position;

FIGURE 5 is an enlarged sectional view taken along line 55 in FIGURE 1; and

FIGURE 6 is a sectional view taken along line 66 in FIGURE 5.

In a sense, the present invention contemplates the provision of a swivel chair including a support column, a seat member rotatably mounted atop said support column and spring means normally resiliently rotatably urging said seat to a predetermined orientation about the axis of said column.

According to a preferred form of the present invention, the support has affixed to its bottom radially projecting legs and terminates at its top in a shallow coupling section of square transverse cross-section surrounded by a coaxial stub shaft of reduced transverse crosssection. includes a centrally located square aperture registering with the column coupling section as well as diametrically opposite depressed peripheral sections and opposite raised sections intermediate the depressed sections. The underface of the chair seat carries a centrally apertured bearing plate which engages the column stub shaft and is supported thereby. A pair of transversely spaced parallel arms are pivoted at opposite ends thereof to the underface of the chair seat and are spring urged toward each other. A cam follower is carried by each of the pivoted arms and engages the cam periphery. The seat A cam is affixed to the support column and- 3,142,471 Patented July 28, 1964 member is thus normally resiliently urged to a forwardly or rearwardly directed position by the arms which are spring urged toward each other and which cause rotation of the seat to a point where the followers register with the cam depressed sections.

Referring now to the drawings, which illustrate a preferred embodiment of the present invention, reference numeral 10 generally designates the improved swivel chair which comprises a base section 11 and a seat section 12. Base section 11 includes a central upright rodshaped support post or column 14 having aflixed to the bottom thereof a plurality of radially projecting, outwardly downwardly inclined legs 15 terminating in depending foot pieces. The upper end of the column 14 is successively reduced in cross-section to provide a central coupling section 16 of square transverse cross-section above which projects a coaxial stub shaft 17 having a groove 18 formed in its peripheral face directly below the top thereof.

Seat section 12 may be of any suitable construction, upholstered or not, as desired, and comprises a seat 19, back rest 20 and side arms 21 joined in the usual fashion. Seat 19 includes a structurally rigid base wall 22 having a central aperture formed therein. A rectangular relatively heavy metal bearing plate 23 is secured to the underface of base Wall 22 by screws 24, and has a circular opening 26 formed therein coaxial with the base wall aperture, and of a diameter substantially equal to that of stub shaft 17.

The seat biasing mechanism includes a flat cam 27 having formed therein a square aperture 28 which snugly registers with and engages column coupling section 16 to effect a rigid connection therebetween. Cam 27 is of symmetrical configuration, including a pair of diametrically opposite raised sections 29 and a pair of diametrically opposite troughs or depressed sections 30, each of which is spaced substantially from adjacent raised sections 29. The surface of cam 29 continuously increases from each of the depressed sections 30 to the raised sections 29.

A fiat mounting ring or annulus 32 is disposed beneath seat base wall 22, coaxial with aperture 26, and has an inside diameter greater than the major dimension of cam 27. Annulus 32 is secured tothe underface of seat base wall 22 by suitable screws and is regularly spaced therefrom by spacer sleeves 34 engaging screws 33 between the confronting faces of base wall 22 and annulus 32.

Pivoted to diametrically opposite points of annulus 32, by means of pivot pins 36, are laterally spaced transversely projecting seat biasing levers 37 extending substantially along opposite sides of annulus 32. Each biasing lever 37 includes a pair of vertically spaced, parallel, upper and lower curved arms 38 and 39 respectively, each pair being connected to annulus 32 by a corresponding pin 36, as aforesaid, the ends of pins 36 being upset to effect securement of arms 38 and 39. The free ends of each pair of arms 38 and 39 are connected by a rivet pin 40 which is laterally spaced from the pivot pin 36 of the opposite arms 38 and 39. Each of arms 38 and' 39 is provided with an inwardly directed ear 41, and a cam follower-defining roller 42 is sandwiched between corresponding pairs of legs 41 and rotatably afiixed thereto by suitable pins 43.

Seat section 12 is mounted atop column 14, the bearing plate aperture 26 registering with stub shaft 17. A split ring 44 engages shaft groove 18 along the bearing plate 23 to lock seat section 12 to column 14 while permitting the rotation thereof. Cam followers 42 are disposed in the plane of cam 27 and are urged into engagement with the edge of cam 27 by a pair of helical tension springs 46 which are connected between adjacent pins 36 and 40 to urge the free ends of biasing levers 37 toward the pivoted ends of the opposing levers.

In operation, seat section 12, when in unstressed condition, normally assumes a forwardly or rearwardly directed orientation and the cam followers 42 engage the cam troughs or depressed sections 30 so that biasing levers 37 are in a contracted condition relative to each other. Upon the swivelling of the seat section either; forwardly or rearwardly from its retracted position, the

biasing levers 37 are spread apart by cam 27 and followers 42 against the tension of the springs 46 and as a result thereof impart a returning moment to the seat section which increases in force as the angle from the retracted position increases. Thus, upon release of the turning torque, the seat section returns to its initial position. However, should the chair seat be swivelled more than 90 from its initial rest position, followers 42 will ride past the cam raised sections 29 to continue the rotation of the seat to its opposite rest position under the influence of the bias levers 37 whereat followers 42 engage opposite cam depressed sections 30.

While there has been described and illustrated a preferred embodiment of the present invention, it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof. Further, it is to be borne in mind that the present invention may be applied to other articles of furniture or office equipment, in addition to chairs. For example, the present invention may be used in connection with desks, display or storage cabinets, tables and, indeed, with any article having a substantially flat portion mounted atop a support member, column or otherwise, and the use of the chair in the drawings and the claims is merely exemplary. Thus, element 12 may be the desk platform, the table or the lower portion of a display or storage cabinet, and the term swivel chair as used in the claims is to be construed to mean any article of house or oflice furni- 4 ture as it is to be similarly construed in the present specification.

Having now described my invention, what I claim and desire to secure by Letters Patent is:

1. A swivel chair comprising. a vertical support column, a seat member mounted atop said column and ropressed sections and raised sections intermediate said depressed sections, a biasing lever pivoted to said seat member for rotation in a horizontal plane, a cam follower mounted on said lever and engaging said cam, and spring means urging said lever and cam follower toward said cam.

2. A swivel chair comprising a vertical support column, a seat member mounted atop said column and rotatable about the longitudinal axis thereof, a cam affixed to said column and lying in a substantially horizontal plane and having a pair of diametrically opposite depressed sections and raised sections intermediate said depressed sections, a pair of biasing levers disposed on opposite sides of said cam and pivoted to said seat member at opposite points thereon for rotation in a horizontal plane, a cam follower mounted on each of said levers and engaging opposite edges of said cam, and spring means urging said levers and cam followers toward said cam.

References Cited in the file of this patent UNITED STATES PATENTS 1,153,634 Levin Sept. 14, 1915 1,666,392 Masury Apr. 17, 1928 1,918,190 Miller July 11, 1933 2,204,218 Hill June 11, 1940 

1. A SWIVEL CHAIR COMPRISING A VERTICAL SUPPORT COLUMN, A SEAT MEMBER MOUNTED ATOP SAID COLUMN AND ROTATABLE ABOUT THE LONGITUDINAL AXIS THEREOF, A CAM AFFIXED TO SAID COLUMN AND LYING IN A SUBSTANTIALLY HORIZONTAL PLANE AND HAVING A PAIR OF DIAMETRICALLY OPPOSITE DEPRESSED SECTIONS AND RAISED SECTIONS INTERMEDIATE SAID DEPRESSED SECTIONS, A BIASING LEVER PIVOTED TO SAID SEAT MEMBER FOR ROTATION IN A HORIZONTAL PLANE, A CAM FOLLOWER MOUNTED ON SAID LEVER AND ENGAGING SAID CAM, AND SPRING MEANS URGING SAID LEVER AND CAM FOLLOWER TOWARD SAID CAM. 